Computer enclosure cooling unit

ABSTRACT

A computer enclosure cooling unit adapted to current dimensional standards which is capable of controlled cooling of individual semiconductor devices as well as of the air circulated within the computer housing. The disclosed invention utilizes Peltier devices, a controller unit, both liquid and gaseous heat exchangers, and low cost construction methods to provide a compact, effective computer enclosure cooling system meeting the cooling needs of current high-speed, heat producing computer systems and components.

This is a continuation of U.S. application Ser. No. 09/434,873, filedNov. 4, 1999, now U.S. Pat. No. 6,196,003.

BACKGROUND OF THE INVENTION

a. Field of the Invention

The present invention is related generally to the field of computerenclosure cooling units. A substantial problem exists in keepingcomputer enclosures cooled. Typically a computer enclosure housesnumerous semiconductor units, certain motorized units, and powersupplies, all of which tend to be in varying degrees inefficient andtherefore heat producing. Semiconductor units typically have an optimaltemperature operating range at or below room temperature (20 degreesCelsius). Most computer enclosures are air cooled with blowers or fanscirculating air from the enclosure into the ambient of the room withinwhich the computer enclosure is located.

More particularly the present invention is related to computer enclosurecooling units that utilize Peltier devices to enhance heat transfer outof the computer enclosure into the air circulated into the room ambient.Peltier devices are well known for the transfer of heat through thedevice induced by electric current flow. Such devices are known to beusefully adapted to enhance heat transfer out of individualsemiconductor devices by conduction.

Yet more particularly, the present invention is related to computerenclosure cooling units utilizing Peltier devices that cool not only theindividual semiconductor devices within the computer, but additionallycool the ambient air within the computer enclosure. As the operatingspeed of the various semiconductor devices within computers increases,the inefficiencies and thus the heat generation of the individualsemiconductor devices, and in particular the central processing unit orCPU generates dramatic quantities of heat. The excess heat generated, inturn, degrades the operation of the individual semiconductor devicefurther, where by a degenerative spiral of operating characteristics isencountered limiting the operating speed of the individual semiconductorunit and thus of the computer.

b. Description of the Prior Art

Computer enclosure cooling systems comprising fans and blowers are wellknown in the art. In fact, several improved blower systems have beendeveloped which create a partial vacuum in the computer enclosure, oralternatively which provide specific ports for air flow into thecomputer enclosure from the room ambient, in order to increase thetransfer of heat out of the computer enclosure into the room ambient.However, all such prior art blower and/or fan systems encounter aproblem, the heat transfer efficiency out of the enclosure is limited bythe temperature differential between the air inside the computerenclosure and the air in the room ambient.

Peltier devices and the use of Peltier devices to transfer heat out ofindividual semiconductor materials and devices is well known. Further,the use of Peltier devices in circuitry to used regulate temperatures ofspecific semiconductor devices is well known. However, transfer of heatout of the entirety of the enclosure, rather than just specificsemiconductor devices is need for optimal cooling of the computerenclosure; in that the density of switches within a specificsemiconductor device is a source of excessive heating and that thedensity of devices, both electronic and electrical, within the computerenclosure is yet another source of excessive heating.

Additionally well know are air circulation systems to transfer heat outof computer enclosures. Some of these air circulation systems have beenconstructed to conform to the physical standards set for computer drivebays. However, even the conformance of the air circulation system to thestandards set for computer drive bays fails to address the need forfocused cooling created by the high operating temperatures of currentlyavailable high-density semiconductor devices.

Finally, the use of refrigeration systems to cool the entirety of theambient in the room containing the computer enclosure is well known. Theexpense of this approach is often prohibitive, as is the physical sizeand placement of the refrigeration system components.

SUMMARY OF THE INVENTION

The instant invention is of a computer enclosure cooling unit thatutilizes Peltier devices to enhance heat transfer out of the computerenclosure and provides both cooling of the ambient air within thecomputer enclosure and cooling of selected individual semiconductordevices within the computer enclosure. The numerous problems noted inthe prior art cooling systems and devices are addressed in the instantinvention and the result is a highly effective, controllable system forcooling a computer enclosure which may be constructed in conformity withexisting standards.

Accordingly, it is an object of this invention to provide a computerenclosure cooling unit which provides high efficiency cooling both ofthe air circulating generally within the computer enclosure and of thespecific semiconductor devices most prolifically heat generating.

It is a further object of this invention to provide a computer enclosurecooling unit which uses the controllability of Peltier devices toregulate the temperature and heat exchange provided by the cooling unitto the computer enclosure and specific semiconductor devices.

It is a yet further object of this invention to provide a computerenclosure cooling unit which doesn't require increased air flow ratesthrough the computer enclosure in order to provide adequate cooling ofboth the enclosure air and specific semiconductor devices.

It is a yet further and final object of this invention to provide acomputer enclosure cooling unit which provides all of theabove-described advantages at a low cost to manufacture, install andoperate.

BRIEF DESCRIPTION OF THE DRAWINGS

While the novel features of the instant invention are set forth withparticularity in the appended claims, a full and complete understandingof the invention can be had by referring to the detailed description ofthe preferred embodiment(s) which are set forth subsequently, and whichare as illustrated in the accompanying drawings, in which:

FIG. 1 is a perspective view of the Computer Enclosure Cooling Unitmounted within a Computer Housing.

FIG. 2A is a top plane view of the Computer Enclosure Cooling Unit.

FIG. 2B is a lateral plane view of the Computer Enclosure Cooling Unit.

FIG. 2C is a front plane view of the Computer Enclosure Cooling Unit

FIG. 2D is a rear plane view of the Computer Enclosure Cooling Unit.

FIG. 3A is a sectional view of the Computer Enclosure Cooling Unit takenalong the line 3A—3A, as shown in FIG. 2A.

FIG. 3B is a sectional view of the Computer Enclosure Cooling Unit takenalong the line 3B—3B, as shown in FIG. 2A.

FIG. 4A is a cutaway perspective view of the Computer Enclosure CoolingUnit displaying the Enclosure Air Cooling Unit.

FIG. 4B is a vertical sectional view of the Computer Enclosure CoolingUnit displaying the Enclosure Air Cooling Unit.

FIG. 5A is cutaway perspective view of the Computer Enclosure CoolingUnit with the Enclosure Air Cooling Unit removed to display the CoolingFluid Cooling Unit.

FIG. 5B is a vertical sectional view of the Computer Enclosure CoolingUnit with the Enclosure Air Cooling Unit removed to display the CoolingFluid Cooling Unit.

FIG. 6A is a cutaway perspective view of the Computer Enclosure CoolingUnit with the Enclosure Air Cooling Unit removed and the Cooling FluidCooling Unit removed, to display the Peltier Heat Exchange Unit.

FIG. 6B is a vertical sectional view of the Computer Enclosure CoolingUnit with the Enclosure Air Cooling Unit removed and the Cooling FluidCooling Unit removed, to display the Peltier Heat Exchange Unit.

FIG. 7A is a cutaway perspective view of the Computer Enclosure CoolingUnit with the Enclosure Air Cooling Unit removed, the Cooling FluidCooling Unit removed, and the Peltier Heat Exchange Unit removed todisplay the Ambient Air Heat Exchange Unit.

FIG. 7B is a vertical sectional view of the Computer Enclosure CoolingUnit with the Enclosure Air Cooling Unit removed, the Cooling FluidCooling Unit removed, and the Peltier Heat Exchange Unit removed, todisplay the Ambient Air Heat Exchange Unit.

FIG. 8A is a perspective view of the Device Heat Exchange Unit mountedon a CPU.

FIG. 8B is a vertical sectional view of the Device Heat Exchange Unitdisplaying the Device Cooling Fluid Chamber and fluid flow path.

FIG. 8C is a horizontal sectional view of the Device Heat Exchange Unitmounted on a CPU.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

As seen in FIG. 1, the instant invention is of a computer enclosurecooling unit 2. The instant invention, in use, as depicted in FIG. 1,would normally be installed into a standard 5.25 inch drive bay 11 in acomputer housing 3. The dimensions of the computer enclosure coolingunit housing 1 are such that the unit may be readily mounted into thespace allocated to a standard hard drive unit within a computer housing3.

Numerous approaches to a solution of the heat generation problemspresent within computer housings 3 have been taken by the industry. Theinstant invention takes the approach of a bifurcated ventilation system,that is, the air circulating for heat exchange to the space outside thecomputer housing 3 does not mix with the air circulating for heatexchange within the computer housing 3. This is important as thehumidity condensation created by the drying effect when the air internalto the computer housing 3 is cooled could destroy the operation of theelectronic components within the computer housing 3. Additionally, theinstant invention may include cooling of individual electroniccomponents within the computer housing 3, as needed; and provides for acontroller unit 7 which may control the temperature of air circulatingwithin the computer housing 3 and the temperature of the cooling fluidor coolant flowing through the cooling fluid tubing 23 to the deviceheat exchanger 5, a liquid coolant heat exchanger which makes a direct,conductive heat exchange with the CPU 25 or other electronic componentselected for individual cooling within the computer housing 3. The CPU25 is shown in FIG. 1 to be mounted on a motherboard 9 which normallywill provide for mounting of numerous other electronic and/or electricalcomponents, any one or more of which electronic and/or electricalcomponents may be the subject of individual cooling by connection ofanother set of cooling fluid tubing 23 to another device heat exchanger5 which is disposed in heat conductive relationship thereto.

Also shown in FIG. 1 are the mounting holes 15, which facilitateconnection of the computer enclosure cooling unit housing 1 to bracketswithin the computer housing 3 which are normally present to secure unitsinserted into one of the 5.25 inch drive bays 11; the ambient air heatexchanger air intake 19 which permits passage of air from the roomambient into the computer enclosure cooling unit 2; the ambient air heatexchanger air exhaust 21 which permits passage of air from within thecomputer enclosure 1 out to the room ambient; and the ribbon cable 17which makes the electrical connection between the computer enclosurecooling unit 2 components and the controller unit 7.

FIGS. 2A, 2B, 2C, and 2D are plane views of the computer enclosurecooling unit housing 1 which show that to the rear of the computerenclosure cooling unit housing 1 are found the enclosure air coolingunit air intake 27 which permits air from within the computer housing 3to flow into the computer enclosure cooling unit housing 1; and theenclosure air cooling unit air exhaust 29 which permits air from withinthe computer enclosure cooling unit housing 1 to flow out into the airwithin the computer housing 3.

FIGS. 3A and 3B are sectional views of the computer enclosure coolingunit 2 which show that the instant invention is constructed inessentially four layers, each of which is herein considered a sub-unit.Working from the top down, the first layer is the enclosure air coolingunit 26, the second layer is the cooling fluid cooling unit 34, thethird layer is the Peltier heat exchange unit 32, and the fourth, orbottom, layer is the ambient air heat exchange unit 60.

The enclosure air cooling unit 26 is shown in detail in FIGS. 4A and 4B.The enclosure air cooling unit 26 comprises an enclosure air coolerblower unit 43, a enclosure air cooling unit air flow baffles 45, anenclosure air cooling unit air intake 27, and an enclosure air coolingunit air exhaust 29. FIG. 4B depicts the direction of air flow internalto the enclosure air cooling unit 26 by arrows 47. Also provided by theenclosure air cooling unit 26 is the upper aperture of a tubularcondensate drain 37. The lower surface of the enclosure air cooling unit26 is beveled, as indicated by the condensate drain flow arrows 49 inFIG. 4B, in the preferred embodiment to cause drainage of condensatefrom the cooled air within the enclosure air cooling unit 26, into thecondensate drain 37, through the cooling fluid cooling unit 34 and thePeltier heat exchange unit 32, to be discharged into the ambient airheat exchanger 60 where the condensate is evaporated into the heated airand discharged into the ambient of the room containing the computerhousing 3.

FIGS. 5A and 5B are two views of the cooling fluid cooling unit 34 ofthe preferred embodiment of the instant invention. The cooling fluidcooling unit 34 comprises a cooling fluid chamber 35, comprising thespace between the enclosure air cooling unit 26 and the Peltier heatexchange unit 32 that is within the computer enclosure cooling unithousing 1, containing cooling fluid tubing 23 which is coiled within.The tubular cooling fluid chamber 35 of the preferred embodiment is inheat conductive contact with the cold side of the Peltier devices 33contained in the Peltier heat exchange unit 32 as shown in FIGS. 6A and6B; and further in heat conductive contact with the lower surface of theenclosure air cooling unit 26. The cooling fluid cooling unit 34provides a pump 31 to circulate the cooling fluid within the coolingfluid tubing 23. Construction of the preferred embodiment provided aledge 51 upon which the pump 31 was mounted within the cooling fluidcooling unit 34.

FIGS. 6A and 6B are two views of the Peltier plate 30 of the preferredembodiment. The Peltier plate 30 comprises a plurality of Peltierdevices 33 in electrical communication with the controller unit 7through the ribbon cable 17. The lower surface of the Peltier plate 30is comprised of heat conductive material, metal in the preferredembodiment, and such lower surface is in heat conductive contact withthe hot side of the Peltier devices 33.

FIGS. 7A and 7B are two views of the ambient air heat exchanger 60. Theambient air heat exchanger 60 provides, in the preferred embodiment, twoambient air heat exchanger blower units 61, ambient air heat exchangerinternal walls 64, two ambient air heat exchanger air intakes 19, andtwo ambient air heat exchanger air exhausts 21. In the preferredembodiment, spacing between the ambient air heat exchanger internalwalls 64 provides ambient air heat exchanger internal air flow chambers39, and air flow, indicated by ambient air heat exchanger air flowarrows 59, is continuous between the ambient air heat exchanger internalair flow chambers 39 by passing through apertures 65 in the ambient airheat exchanger internal walls 64. All materials in the ambient air heatexchanger 60 are, in the preferred embodiment, comprised of heatconductive materials, arranged in a maze, and facilitate the transfer ofheat from the hot side of the Peltier devices 33 into the air flow whichdischarges out of the ambient air heat exchanger air exhausts 21 intothe room ambient.

FIGS. 8A, 8B and 8C are of the device heat exchanger 5 which, in thepreferred embodiment is mounted on a CPU 25, although the particularsemiconductor device upon which the device heat exchanger 5 is mountedmay change with the needs of the particular computer being cooled.Additionally, there may be a plurality of device heat exchangers 5 witheach such heat exchanger being mounted on a separate semiconductordevice in a situation where multiple semiconductor devices within aparticular computer housing 3 require individual cooling. Finally, it iscontemplated that in another preferred embodiment, the device heatexchanger 5 may be integrally a part of the semiconductor device suchthat the semiconductor packaging includes a device heat exchanger 5 andfittings for attachment of cooling fluid tubing 23.

As seen in FIG. 8A, the cooling fluid flow within the cooling fluidtubing 23 is in fluid communication with the interior of the device heatexchanger 5. Such communication may be attained by attaching orconnecting the cooling fluid tubing 23 to the device heat exchanger 5,or by simply having the cooling fluid tubing 23 be a continuous tubularconstruction with device cooling fluid chamber 68 within the device heatexchanger 5. In the preferred embodiment, as shown in FIG. 8B, theinterior of the device heat exchanger 5 is a maze of fluid bafflescreating a device cooling fluid chamber 68 which is designed to lengthenthe path taken by the cooling fluid in order to maximize the heattransfer between the cooling fluid and the device heat exchanger 5 andthus to the thermal paste 71 and the CPU 25. FIG. 8C shows theattachment of the device heat exchanger 5 to the CPU 25 as being simplya pressed fit of the thermal paste 71, which fills a cavity in thebottom structure of the exterior of the device heat exchanger 5, ontothe top of the CPU 25. This press fit of the thermal paste 71 onto theCPU 25 was chosen because many currently available CPUs 25 have a heatsink structure built onto their packaging in order to dissipateexcessive heat. The thermal past 71 will conveniently mold itself aroundthe heat sink structure. Additionally, a device temperature sensor 69 isshown in FIG. 8C of the preferred embodiment. The device temperaturesensor 69 is in electrical communication with the controller unit 7which uses various sensor feedbacks from the computer enclosure coolingunit 2 to control the speed of the enclosure air cooling unit blowerunit 43, the speed of the pump 31, the speed of the ambient air heatexchanger blower unit 61, and the number of Peltier devices 33 which areturned on as well as the current flow through each such turned onPeltier device 33. The preferred embodiment of the computer enclosurecooling unit 2 includes several sensors, air flow sensors 55, airtemperature sensors 57, and a device temperature sensor 69.

In operation, the preferred embodiment of the instant invention 2 heatis discharged from the computer enclosure cooling unit 2 and into theambient of the room within which the computer housing 3 sits bycirculating the ambient air from the room within which the computerhousing 3 sits through the ambient air heat exchanger 60. By definition,the temperature of the ambient air of the room within which the computerhousing 3 sits is room temperature, and a breakdown of the temperaturecontrol system in the room's ambient air outside the computer housing 3is not expected to be compensated for by the instant invention althoughvariation of the room's ambient air temperature can be compensated forover a large range of room temperatures by the instant invention.Typically, the ambient air in the room containing the computer housing 3can be expected to have a reasonable humidity, something less than onehundred percent. Thus, the heat transfer from the computer enclosurecooling unit 2 to the ambient air within the room will cause anexpansion of the heated air and a localized decrease in the humidity.This localized, within the ambient air heat exchanger 60, is utilized inthe instant invention to evaporate the condensate drained into theambient air heat exchanger 60 from the enclosure heat exchanger throughthe condensate drain 37. Additionally, the flow rate of the aircirculating within the ambient air heat exchanger 60 may not be greaterthan the flow rate of the air circulating within the enclosure heatexchanger in order not to create a low pressure region at the lower endof the condensate drain 37 which would interfere with the preferreddirection of condensate flow through the condensate drain. The hot sideof the Peltier devices 33 are in heat transfer communication with theair circulating within the ambient air heat exchanger 60. In thepreferred embodiment, this heat transfer communication is accomplishedby construction of the Peltier plate 30 in such fashion that the hotside of the Peltier devices 33 are in physical contact with the heatconductive metal which simultaneously comprises the bottom of thePeltier plate 30 and top of the ambient air heat exchanger 60. Ambientroom air circulated through the ambient air heat exchanger 60 is therebyheated by contact with the Peltier plate's 30 bottom surface which isthe ambient air heat exchanger's 60 upper surface. Circulation of theair within the ambient air heat exchanger 60 is assured by the presenceof the ambient air heat exchanger blower units 61 and the arrangement ofair deflection baffles (the ambient air heat exchanger internal walls 64of the preferred embodiment). Greater heat exchange may be achieved bynumerous other arrangements of the air deflection baffles, but in thepreferred embodiment the ambient air heat exchanger internal walls 64(baffles) simply form a maze, lengthening the path taken by thecirculating air, by using strips of sheet metal as the ambient air heatexchanger internal walls 64 with apertures 65, which are stamped out ofthe strips, for air flow in order to decrease construction costs.

The Peltier heat exchange unit 32 of the preferred embodiment comprisesa Peltier plate 30 whose bottom surface is constructed of heatconductive metal to which the hot side of the Peltier devices 33 arephysically mounted and a top surface constructed of heat conductivemetal to which the cold side of the Peltier devices 33 are physicallyconnected. Thus the Peltier heat exchange unit 32 simply transfers heatthrough the Peltier devices 33 from the top surface of the Peltier heatexchange unit 32 to the bottom surface of the Peltier heat exchange unit32. The top surface of the Peltier heat exchange unit 32 is, in thepreferred embodiment constructed of a heat conductive sheet of metalwhich also serves as the bottom surface of the cooling fluid coolingunit 32, a liquid coolant heat exchanger. The rate of heat transferbetween the top surface of the Peltier heat exchange unit 32 and thebottom surface of the Peltier plate 30 and thus of the Peltier heatexchange unit 32 is controlled by the number of Peltier devices 33 thatare switched on and the current flow that is provided to each individualPeltier device 33. The preferred embodiment provides a controller unit 7which has as inputs the outputs of the various sensors within thecomputer enclosure cooling unit 1 and has as outputs the currentsupplied to the ambient air heat exchanger blower units 61, the currentsupplied to the pump 31, the current supplied to the enclosure aircooling blower unit 43, as well as the current supplied to each of thePeltier devices 33. All of the inputs and outputs of the controller unit7 are electrically connected to the various sensors and controlleddevices through the ribbon cable 17. The controller unit 7 of thepreferred embodiment is a computer card containing programmablecircuitry with a graphical user interface permitting the computeroperator to make settings for optimum computer enclosure andsemiconductor device temperatures. Clearly, the controller unit 7 may beas simple as a set of voltage and current dividers or switches preset toan average desirable set of operating conditions or as sophisticated ascircuitry driven by artificial intelligence to continually adjust airflow rates, fluid flow rates, and the number, identity, and current flowthrough individual Peltier devices 33 in order to continually maintainoptimal operating temperature for a particular semiconductor device andambient air temperature within the computer housing 3.

While a single Peltier plate 30 is utilized in the preferred embodiment,the enhanced heat transfer between sub-units of the computer enclosurecooling unit 2 made possible by the Peltier devices 33 may beadvantageously utilized between multiple sub-units. For example aPeltier plate 30 could additionally be inserted between the coolingfluid cooling unit 34 and the enclosure air cooling unit 26. Or, in aslightly different configuration, the heat conductive surface which isthe lower surface of the cooling fluid cooling unit 34 in the preferredembodiment could be utilized for both fluid cooling and air cooling byeither splitting the surface between the two functions or byinterspersing the air circulation areas and the fluid circulation areasover the single heat conductive surface. In this fashion, there would beno distinct sub-unit for the enclosure air cooling unit 26, there wouldrather be a single combined enclosure air cooling unit 26 and coolingfluid cooling unit 34. For purposes of decreasing the height and spaceconsumption of the computer enclosure cooling unit 2, such sharing ofthe heat conductive surface which is the lower surface of the coolingfluid cooling unit 34 may be advantageous. Such utilization of multiplePeltier plates 30 or of shared heat exchange surfaces do not depart fromthe teachings of the preferred embodiment.

The fluid heat exchanger (the cooling fluid cooling unit 34 of thepreferred embodiment) is comprised of heat conductive tubing in physicalcontact with a floor which is the heat conductive sheet metal comprisingthe upper surface of the Peltier heat exchange unit 32 and with aceiling which is the lower surface of the heat conductive sheet metalcomprising the lower surface of the enclosure air cooling unit 26. Thusfluid cooling takes place by heat exchange from the cooling fluid to theheat conductive tubing (the cooling fluid chamber 35 of the preferredembodiment) in which the cooling fluid is contained, from the heatconductive tubing to the heat conductive sheet metal comprising thelower surface of the cooling fluid cooling unit 34, from the heatconductive lower surface of the cooling fluid cooling unit 34 to thecold side of the Peltier devices 33 that are in physical contact withthe underside of the heat conductive sheet metal that is the lowersurface of the cooling fluid cooling unit 34, across the Peltier devices33 from the cold side to the hot side, from the hot side of the Peltierdevices 33 to the lower surface of the Peltier plate 30, from the upperside of the heat conductive metal comprising the lower surface of thePeltier plate 30 to the air circulating within the ambient air heatexchanger 60, and from thence is exhausted out through the ambient airheat exchanger air exhaust 21 out into the ambient of the roomcontaining the computer housing 3. The cooling fluid flow directionwithin the device heat exchanger 5 is shown in FIG. 8B by device coolingfluid flow arrows 67 thus the direction of fluid flow within the coolingfluid tubing 23 is defined. As seen in FIG. 3, the cooling fluid flowsout of the cooling fluid cooling unit 34 of the computer enclosurecooling unit 2 through the cooling fluid tubing 23 and is circulatedthrough a device cooling fluid chamber 68 (shown in FIG. 8) which is inheat exchange communication with a semiconductor device, in thepreferred embodiment a single CPU 25. There may be, by obviousmodification of the cooling fluid tubing 23, a plurality of the deviceheat exchangers 5 cooling a plurality of semiconductor devices. Thedevice heat exchanger 5 of the preferred embodiment is simply a fluidflow maze whose baffles and walls are constructed of heat conductivematerial. Numerous baffle configurations may be utilized to optimizeturbulence and/or lengthen the effective fluid flow path in order tooptimize heat transfer between the cooling fluid and the heat conductivewalls and baffles which form the device cooling fluid chamber 68 of thedevice heat exchanger 5. The device heat exchanger 5 is in heat exchangecommunication with the semiconductor device to be cooled or temperaturecontrolled. The preferred embodiment monitors the temperature of thesemiconductor device being cooled with the device temperature sensor 69and utilizes thermal paste 71 to both affix the device heat exchanger 5to the semiconductor device (CPU 25 in the preferred embodiment) beingcooled and enhance heat transfer between the semiconductor device beingcooled and the cooling fluid being circulated through the cooling fluidtubing 23 and the device cooling fluid chamber 68 within the device heatexchanger 5. Further, the thermal paste 71 serves to both put the devicetemperature sensor 71 in heat flow communication with the semiconductordevice being cooled and to affix the device temperature sensor 71 to thedevice heat exchanger 5.

Heat flow communication between the cooling fluid within the coolingfluid cooling unit 34 and the heat conductive material comprising thelower surface of the enclosure air cooling unit 26 acts to provide acool surface for heat exchange with the air circulating within theenclosure air cooling unit 26. The preferred embodiment, created withcost considerations foremost in mind, utilizes simple heat conductivesheet metal for the surfaces between the enclosure air cooling unit 26and the cooling fluid cooling unit 34, between the cooling fluid coolingunit 34 and the Peltier plate 30, between the Peltier plate 30 and theambient air heat exchanger 60, and for the construction of the computerenclosure cooling unit housing 1 which serves as the outer walls of allsub-units as well as the upper surface of the enclosure air cooling unit26 and the lower surface of the ambient air heat exchanger 60. Thisconstruction of the computer enclosure cooling unit housing 1 from heatconductive sheet metal is consistent with current standardized size,shape and materials for peripherals intended to be installed, as thepreferred embodiment is, in a 5.25 inch drive bay 11; but is non-optimalas the heat conductive sheet metal provides heat flow communication in anegative feedback loop around the various sub-units of the computerenclosure cooling unit 2 and thereby creates substantial inefficiencies.A second embodiment of the instant invention provides that the computerenclosure cooling unit housing 1 be constructed of non-heat conductivematerials while maintaining the use of heat conductive material for thesurfaces between the enclosure air cooling unit 26 and the cooling fluidcooling unit 34, between the cooling fluid cooling unit 34 and thePeltier plate 30, between the Peltier plate 30 and the ambient air heatexchanger 60.

The enclosure air cooling unit 26 of the preferred embodiment provides aminimum of air baffles for heat exchange to the air circulating withinit. This construction has been found to be adequate to provide modestcooling of the interior of the computer housing 3. Current art for thecooling of the interior of computer housings 3 depends on air leakageinto the enclosure formed by the computer housing 3 and fans to exhaustthat air which is leaking in. Some prior art specifically provides forair flow into the enclosure formed by the computer housing 3 from theambient in the room enclosing the computer housing 3. However, enhancedcooling of the interior of the computer housing 3 can be achieved byincreasing the turbulence of the air and increasing the number andcomplexity of arrangement of the air baffles within the enclosure aircooling unit 26. Enhanced cooling of the air exhaust into the interiorof the computer housing 3 from the enclosure air cooling unit 26 raisesthe possibility of condensate forming within the interior of thecomputer housing 3 and thereby creating shorts around the variouselectrical and electronic components therein. Such possibility ofcondensate forming is created by the interaction of the cool, partiallydried, air exhaust into the interior of the computer housing 3 from theair exhaust 29 of the enclosure air cooling unit 26 with the relativelymoist air leaking into the interior of the computer housing 3 from theambient in the room containing the computer housing 3. This possibilityof condensate formation within the interior of the computer housing 3can be substantially eliminated through the use of positive air pressurewithin the interior of the computer housing 3. Positive air pressurewould force air leakage out of the interior of the computer housing 3,thereby eliminating the source of humidity in the air interior to thecomputer housing 3. Positive air pressure can be achieved by moving theair input to the enclosure air cooling unit 26 such that it permits airintake from the ambient air in the room containing the computerenclosure rather than from the interior of the computer housing 3.Accordingly, a third embodiment of the instant invention provides forthe enclosure air cooling unit air intake 27 to be located such that airis input to the enclosure air cooling unit 26 from the ambient air inthe room containing the computer housing 3 and not from the interior ofthe computer housing 3. In the third embodiment, it is necessary thatthe local air circulation paths created within the ambient air of theroom containing the computer housing 3 by the air intake to theenclosure air cooling unit 26 on the one hand and the air exhaust fromthe ambient air heat exchanger 60 on the other hand be kept apart anddistinct.

Cooling of the air within the enclosure air cooling unit 26, whetherconfigured as in the preferred embodiment or in the third embodiment,creates a condensate on the cooled surface(s) where the heat exchangewith the circulating air takes place. In the preferred embodiment thelower surface of the enclosure air cooling unit 26 is beveled or slopedtoward a condensate drain 37. The condensate drain 37 comprises a tubehaving its upper end opening in the lower surface of the enclosure aircooling unit 26 and its lower end opening in the upper surface of theambient air heat exchanger 60. The condensate drain 37 is ideallycomprised of non-heat conductive materials, alternatively, thecondensate drain 37 may be heat insulated from the heat conductivesurfaces that it passes through. Freezing of the condensate within thetube comprising the condensate drain 37 as it passes through the uppersurface of the Peltier plate 30 must be avoided. A yet third, and not asdesirable, solution to avoid condensate freezing is to make the tubingcomprising the condensate drain 37 highly heat conductive such thatefficiency of the Peltier plate 30 is sacrificed in the vicinity of thecondensate drain's 37 passage through the upper surface of the Peltierplate 30 by heat feedback from the lower surface of the Peltier plate30.

A fourth embodiment of the instant invention provides that the airexhaust from the computer housing 3, having been cooled by the airexhaust from the enclosure air cooling unit air exhaust 29, is input tothe ambient air heat exchanger air intake 19. Thus a single path for airflow from and to the ambient air within the room containing the computerhousing 3 is established. Greater efficiency of heat exchange over theentirety of the computer enclosure cooling unit 2 can be achieved by thefourth embodiment, but at a cost of increased tubing or piping tocontain the flow of air from the air exhaust of the enclosure aircooling unit 26 to the ambient air heat exchanger air intake 19.

A yet fifth embodiment of the instant invention provides that both theair exhaust from the computer housing 3 is input to the ambient air heatexchanger air intake 19 and that the air intake to the enclosure aircooling unit 26 be positioned to permit air intake from the ambient airin the room containing the computer housing 3 and not from the interiorof the computer housing 3. The fifth embodiment, in combination with theabove-described possible enhancements to the air baffle configuration ofthe enclosure air cooling unit 26 provides a superior computer enclosurecooling unit 2, albeit at greater cost.

While the preferred embodiments of the instant invention have beendescribed in substantial detail and fully and completely hereinabove, itwill be apparent to one skilled in the art that numerous variations ofthe instant invention may be made without departing from the spirit andscope of the instant invention, and accordingly the instant invention isto be limited only by the following claims.

DESCRIPTION OF NUMERIC REFERENCES

1. Computer Enclosure Cooling Unit Housing

2. Computer Enclosure Cooling Unit

3. Computer Housing

5. CPU Cooler

9. Motherboard

7. Controller Unit

11. 5.25′ Drive Bays

13. 3.5″ Drive Bay

15. Mounting Holes

17. Ribbon Cable

19. Ambient Air Heat Exchanger Air Intake (Air Intake)

21. Ambient Air Heat Exchanger Air Exhaust (Air Exhaust)

23. Cooling Fluid Tubing

25. CPU

26. Enclosure Air Cooling Unit

27. Enclosure Air Cooling Unit Air Intake

29. Enclosure Air Cooling Unit Air Exhaust

30. Peltier Plate

31. Pump

32. Peltier Heat Exchange Unit

33. Peltier Device

34. Cooling Fluid Cooling Unit

35. Device Heat Exchanger

37. Condensate Drain

39. Ambient Air Heat Exchanger Air Flow Chamber

43. Enclosure Air Cooling Unit Blower Unit

45. Enclosure Air Cooling Unit Air Flow Baffles

47. Enclosure Air Cooling Unit Air Flow Arrows

49. Condensate Drain Flow Arrows

51. I″ Ledge Created by Extended Lower Level

53. Pettier Wiring

55. Air Flow Sensor

57. Air Temp Sensor

59. Ambient Air Heat Exchanger Air Flow Arrows

60. Ambient Air Heat Exchanger

61. Ambient Air Heat Exchanger Blower Unit

63. Ambient Air Heat Exchanger Blower Unit Wiring

64. Ambient Air Heat Exchanger Internal Walls

65. Apertures in Ambient Air Heat Exchanger Internal Walls

67. Device Cooling Fluid Flow Arrows

68. Device Cooling Fluid Chamber

69. Device Temperature Sensor

71. Thermal Paste

What is claimed is:
 1. An enclosure cooling unit which comprises a firstheat exchanger, a second heat exchanger, a third heat exchanger, and oneor more Peltier devices; wherein said first heat exchanger transfersheat from said enclosure cooling unit to the ambient air outside saidenclosure, said second heat exchanger transfers heat from the air withinsaid enclosure to said enclosure cooling unit, said third heat exchangertransfers heat from cooling fluid circulating within said enclosure tosaid ambient air, said one or more Peltier devices transfer heat fromsaid second heat exchanger to said first heat exchanger, and said one ormore Peltier devices transfer heat from said second heat exchanger tosaid third heat exchanger.
 2. The invention of claim 1 additionallycomprising one or more additional heat exchangers Wherein said enclosureadditionally contains one or more heat producing components, and Whereineach of said additional heat exchangers transfers heat from one or moreof said heat producing components to said cooling fluid.
 3. Theinvention of claim 1 additionally comprising a controller unit andsensors wherein said sensors detect various temperature and flow rateswithin said enclosure cooling unit, said sensors provide informationregarding said detected temperature and flow rates to said controller,said controller provides voltages and currents to electrical and/orelectronic components within said enclosure cooling unit, and saidcontroller utilizes said detected temperature and flow rates todetermine said voltages and currents.
 4. An enclosure cooling unitcomprising a first heat exchanger, a second heat exchanger, a third heatexchanger, and one or more Peltier devices; wherein said first heatexchanger transfers heat from said enclosure cooling unit to the ambientair outside said enclosure, said second heat exchanger transfers heatfrom the air within said enclosure to said enclosure cooling unit, saidthird heat exchanger transfers heat from cooling fluid circulatingwithin said enclosure to said enclosure cooling unit, and said one ormore Peltier devices transfer heat from said second heat exchanger tosaid first heat exchanger.
 5. The invention of claim 4 additionallycomprising one or more additional heat exchangers wherein said enclosureadditionally contains one or more heat producing components, and whereineach of said additional heat exchangers transfers heat from one or moreof said heat producing components to said cooling fluid.
 6. Theinvention of claim 4 additionally comprising a controller unit andsensors wherein said sensors detect various temperature and flow rateswithin said enclosure cooling unit, said sensors provide informationregarding said detected temperature and flow rates to said controller,said controller provides voltages and currents to electrical and/orelectronic components within said enclosure cooling unit, and saidcontroller utilizes said detected temperature and flow rates todetermine said voltages and currents.
 7. An enclosure cooling unitcomprising a first heat exchanger, a second heat exchanger, a third heatexchanger, and one or more Peltier devices; wherein said first heatexchanger transfers heat from said enclosure cooling unit to the ambientair outside said enclosure, said second heat exchanger transfers heatfrom cooling fluid circulating within said enclosure to said enclosurecooling unit, said third heat exchanger transfers heat from the airwithin said enclosure to said cooling fluid, and said one or morePeltier devices transfer heat from said second heat exchanger to saidfirst heat exchanger.
 8. The invention of claim 7 additionallycomprising one or more additional heat exchangers wherein said enclosureadditionally contains one or more heat producing components, and whereineach of said additional heat exchangers transfers heat from one or moreof said heat producing components to said cooling fluid.
 9. Theinvention of claim 7 additionally comprising a controller unit andsensors wherein said sensors detect various temperature and flow rateswithin said enclosure cooling unit, said sensors provide informationregarding said detected temperature and flow rates to said controller,said controller provides voltages and currents to electrical and/orelectronic components within said enclosure cooling unit, and saidcontroller utilizes said detected temperature and flow rates todetermine said voltages and currents.
 10. The invention of claim 7wherein said one or more Peltier devices transfer heat from said thirdheat exchanger to said second heat exchanger.
 11. The invention of claim7 wherein said one or more Peltier devices transfer heat from said thirdheat exchanger to said first heat exchanger.